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Conference and workshop papers:
MOSEL-2 - A Compact But Versatile Model Description Language And Its Evaluation Environment
Proc. of the Workshop MMBnet 2005
Publisher: University of Hamburg,
Keywords: MOSEL-2; Model description language; Evaluation environment; Performance modeling
Abstract: In this paper we present the current version of the MOdeling, Specification and Evaluation Language MOSEL-2 and show its applicability for performance and reliability modeling and evaluation of systems with Markovian and non-Markovian behavior. The tool MOSEL-2 consists of two major components: the description language and the evaluation environment. The description language is the core element of MOSEL-2 and provides a high-level means for specifying models, performance measures, and the graphical presentation of the results of these measures. MOSEL-2?s evaluation environment includes a set of model translators that allow automatic translation of MOSEL-2 models to the model descriptions of several third-party performance evaluation tools. MOSEL-2 uses these tools to evaluate the model by numerical analysis or simulation. The results returned are collected by MOSEL-2 and presented in a unified textual and graphical form. This novel concept exempts the users from learning a new model specification language and rewriting all models each time they have to change a probability distribution within their models. A new and unique concept has been added that allows the automatic approximation of non-Markovian distributions by Markovian constructs. The goal of our ongoing research is to enhance the modeling and evaluation power of MOSEL-2 steadily. This paper aims to give an introduction to the current version of the MOSEL-2 language and its evaluation environment demonstrating the most recent improvements.
Conference and workshop papers:
Modelling a single GSM/GPRS cell with delay tolerant voice calls using MOSEL-2
In, editor, Proc. of the 7th UK Simulation Conf. (UKSIM 2004) , page 88--94.
Keywords: MOSEL-2; System description language; GSM/GPRS; DeTVoC; non-Markovian distributions; IGL
Abstract: In this paper we introduce the new version of the MOdelling, Specification and Evaluation Language -- now called MOSEL-2 -- and prove its applicability for performance modelling of mobile networks with non-Markovian models. Like its predecessor MOSEL [Al-Begain et al, 2001], MOSEL-2 was developed at the Institute for Operating Systems at the University of Erlangen-Nuernberg. In contrast to many specification languages of existing performance modelling and evaluation tools, which often tend to be too verbose, most MOSEL-2 specifications are compact but anyhow easy to understand. Moreover, MOSEL-2 provides means by which many interesting performance or reliability measures and the graphical presentation of them can be specified straightforwardly. It is especially easy to evaluate a model with different sets of system parameters. The benefit of MOSEL-2 -- especially for the practitioner from the industry -- lies in its modelling environment: A MOSEL-2 model is automatically translated into various tool-specific system descriptions and then analysed or simulated by the appropriate tools. This exempts the modeller from the time-consuming task of learning different modelling languages. The following tools and evaluation methods are currently supported by MOSEL-2: MOSES [Bolch et al, 1994] provides several iterative and direct methods (Jacobi, Gauss Seidel, LPU, Crout and Grassmann) for analysing Markovian models, SPNP [Hirel et al, 2000] provides several numerical methods for solving Markovian models and discrete event simulation for evaluating non-Markovian models like extended stochastic Petri nets (ESPNs) and TimeNET [Zimmermann et al, 1999] provides numerical methods for solving Markovian and a restricted class of models with non-exponentially distributed transitions and moreover is able to simulate extended deterministic stochastic Petri nets (eDSPNs). Nevertheless, currently more endeavours are made to include even more evaluation tools and pre-processor concepts to enhance the modelling and evaluation power of MOSEL-2. This Paper aims to give an introduction to the MOSEL-2 language and environment and describe how easily the air interface of a GSM/GPRS cell can be modelled.